Glass-holding table.



Patented Aug. 29, |899.

G. A. MARSH. GLASS HOLDING TABLE.

(Application led Feb. 7, 1898,)

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UN-rrnn STATES PATENT rricn.

GEORGE A. MARSH, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TOv THE MARSHPLATE GLASS COMPANY, OF SAME PLACE.

GLASSHHOLDING TABLE.

SPECIFICATION forming part of Letters Patent No. 631,856, dated August29, 1899. Application filed February', 1898. Serial No. 669,438. (Nomodel.)

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Be it known that I, GEORGE A. MARSH, of Pittsburg, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovement in Glass-Holding Tables, of which the following is a full,clear, and exact description, reference being had to A the accompanyingdrawings, forming part of this specification, in which Figure 1l is atop plan view of a glass-holding table constructed in accordance with myinvention. Fig. 2 is a longitudinal section of the same with the porouspacking in place, and Fig. 3 is an enlarged detail showing the relativearrangement of the air and water channels at the corner of one sectionof the table.

My invention relates to that class of vacuum-tables described in mycopending application, Serial No. 669,437, filed February 7, 1898,wherein a substantial portion of the face constitutes a flatsupporting-surface, from between which and the glass sheets the air isexhausted, and it is designed to increase the gripping power of suchtable upon the sheets of glass laid thereon.

In the drawings, 2'represents a table which is cast in six sections,each having a iiat top and provided with alternate interior water andvacuum chambers 3 and 4. The vacuumchambers extend alternately from oneend of the section to the points near the opposite end, thus giving aconnection between the opposite ends of the fluid-chambers and aording acontinuous circuit for the water or other iuid employed in each section.In the upper face of each section is provided a small groove 5,extending entirely around it near the edge and connected by small holeswith the water-chambers. Inside this channel I provide a sunken channelor groove 6, which extends in parallelism' with the water-channels andwhich in the end sections extends around two sides of the face, while inthe intermediate sections it extends along the outer side only. Thegroove or channel 6 is connected by small branch channels 7 with certainof the holes 8, which lead into the vacuum-chainbers, and is designed toincrease the effective area for the vacuum, this increasedvacuum-surface being preferably located near the edge portions of thetable. The main portion of its face thus constitutes a plain flatsurface with the small vacuum-holes and water-channels therein. Viththis table I employ a iiat sheet of porous packing 9, which is laid overthe entire top of the table,and upon this are placed the glass sheets with their edges spaced between the holes and table. IVith thisconstruction the operation is the same as with the table of myapplication above referred to, the water seeping up through the channelssealing the edges of the glass sheets and moistening them, while at thesame time this water controls the heat of the table. The advantages ofthis form of top or bearing face result from the use of the additionalgrooves which are connected with the vacuumholes and which enable thevacuum to more tirmly hold the glass sheets in place.

Many variations in the form and length of the grooved channels may bemade without departing from my invention, since IVhat I claim is- 1. Aglass-holding table having a substantial portion of its faceconstituting a iiat supporting-surface and provided with perforationsleading to a vacuum apparatus, said tace having a groove near its edgeand connected to the vacuum-holes.

2. A glass-holding table having a substantial portion of its faceconstituting a iiatbearing-surface and having holes leading to a vacuumapparatus, said face havinga groove connected with the vacuum-holes,andasealing means surrounding said surface.

3. A glass-holding table having a substantial portion of its faceconstituting a flat bearing-surface and having holes leading to a vacuumapparatus, said face havinga groove connected with the vacuum-holes,anda chan nel around the surface connected to a fluidchamber.

In testimony whereof I have hereunto set my hand.

G. I. HoLDsHir, C. E. MACKOWN.

